Can Self Propelled Mowers Climb Up Hills When Not Cutting?

Can Self Propelled Mowers Climb Up Hills When Not Cutting? Self-propelled lawnmowers work on a drive system (making them vehicle-like) that requires the operator to squeeze a bar (called a “bail”) on the handle to engage the mower. After that, the mower moves forward on its own (you don’t have to push it). Do reel